I don't have or play black ops, but if you check in the software when you read the settings that are programmed into the controller by default, mode 4 is black ops and I think it was set to 8.5 (not entirely sure) but some of the default speeds didn't work well for me so I tried my own custom speeds. What guns do you usually use that you plan on using rapidfire for? The only threads I saw about black ops were for the macro controller and that software is different so you can't really use settings for the macro on the ragnarok I don't think.
Whatever guns, attachments, and perks you plan on using, put them on a few classes in a custom private game, try out mode 4 which is the default black ops speed and if it isn't good all you have to do is plug in your controller, type in a different speed under that mode to replace the 7.2. Start in increments of 1 SPS (say try like 8 SPS if 7.2 is too slow, then fine tune it to tenths of a shot if you go too high which will make the gun studder or not shoot fast at all (8.1, 8.2, 7.5, etc.)